Previous project phase (2014 - 2017)
PD Dr. Jochen Krauss
Prof. Dr. Martin Müller
Dependence of endophytic fungus - grass symbioses on land-use intensity (DEFENSE)
Endophytic fungi in cool-season grass species (Poaceae) produce herbivore-toxic alkaloids which can affect species communities and ecosystem functioning. These alkaloids can be toxic for vertebrate (e.g. cattle, sheep, horses) and invertebrate herbivores, depending on the concentration and composition of produced alkaloids. If infection rates of grass species and alkaloid production depend on land-use intensity is not well known. Similarly, the effects of different species of endophytic fungus and host grass species on herbivory rates and herbivore diversity is unknown.
In this project we like to quantify the infection rates (occurrence and abundance) and alkaloid concentrations of Poaceae species in the 150 grassland EPs of the Biodiversity Exploratories.
We collected more than 600 grass samples of the perennial ryegrass Lolium perenne in 2014 and will detect the endophytic fungus Neotyphodium lolii using immunoplot assays and qPCR of genomic DNA. We will also quantify the alkaloids using an UPLC-Tandem-MS. We also plan to sample other Poacea species, which occur in reasonable abundances in the exploratory grasslands to identify possible infections of the Neotyphodium/Epichloë species group and to detect their alkaloid profiles. In a last subproject we will collect again samples of Lolium perenne on the grasslands and will use barcoding techniques to detect the endophyte diversity.
With our data we like to address the following key research questions focusing on the diversity of endophytic fungus - host grass symbiosis and ecosystem functioning of infected host grass:
1. Which endophytic fungus - grass symbioses are present in grasslands and are they affected by land-use intensity?
2. Are alkaloid profiles and concentrations produced by endophyte-grass symbioses in the biodiversity exploratories toxic for herbivores?
Previous project contribution of PD Dr. Jochen Krauss: BATMAN